Presentazione di PowerPoint by CqxP6z

VIEWS: 5 PAGES: 22

									A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




   M.G.Bagliesi (a), P.Maestro (a), P.S.Marrocchesi (a), M.Meucci (a), V.Millucci (a),
   F.Morsani (b), R.Paoletti (a), F.Pilo (a), A.Scribano (a), N.Turini (a), G. Valle (a)


                       (a) University of Siena - INFN Gruppo Collegato, Italy
                     (b) Istituto Nazionale di Fisica Nucleare INFN - Pisa, Italy


                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                                     requir
                                                       e




                                    high dynamic range
                                    low-noise

                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




For imaging calorimeters                                                      charge values ranging
 with MAPMT read-out,                                                          from a few tens of fC
   the high gain of the                    results in                   (for minimum ionizing particles)
     photodetector at                                                       to several hundreds of pC
  operating conditions                                                      (for high energy showers)

                                              The idea !


               Our group developed a front-end ASIC where
        each input signal is split into three equal signals and, then,
     each branch is mirrored with different scaling: 1/1, 1/8 and 1/80.

           The total number of read-out channels is multiplied by 3

                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002


          A hybrid which houses 12 chip-sets was developed by Ideas ASA
          (Norway) as a joint project with the University of Siena and INFN.

          Each chip-set consists of two chips:
                                     ICON_4CH
                                     VA4_PMT
          and has the capability to read-out four anodes of a MAPMT.

          The hybrid can eventually house 12 TA-chips (based on the
          TA32CG architecture, Ideas ASA, Norway) to give trigger capability
          to the system.

          Our read-out system prototype is a board with standard VME
          interface.

          The hybrid is implemented as a piggyback board placed on top of
          this VME-board by means of 100mil pitch double-row header
          connectors
                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002


                                                                                             ICON_4CH




                                                                                           VA
                                                                                           (+ optional TA)
         ~10 cm




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                                                The ICON_4CH has 4 inputs
                                                                Input signals are split into three equal
                                                            signals by a current conveyer
                                                                Each branch mirrors the input with
                                                            different scaling: 1/1, 1/8 and 1/80 and
                                                            is linear for input charge values below
                                                            ~120 pC, ~1050 pC and ~4250 pC
                                                            respectively
                                                                Since each mirrored signal has its
                                                            own output pad, this gives 12 output
                                                            pads
                                                                Power consumption in quiescent
                                                            state is ~3.3 mW (~0.83 mW/channel)


                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                                                    It is a 12 channel charge sensitive
                                                                    preamplifier-shaper circuit with:
                                                                          low noise (~10 fC),
                                                                          low power consumption: ~34
                                                                      mW (~2.8 mW/channels),
                                                                          high dynamic range (± 32.5 pC),
                                                                          simultaneous sample-and-hold,
                                                                          multiplexed analog read-out,
                                                                          calibration facilities,
                                                                          programmable gain in the
                                                                      preamplifiers




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002



          ICON_4CH                             VA4_PMT




                                                                                      PRINCIPLE OF THE
                                                                                   TWO-CHIP STRUCTURE
                                                                                   for one input channel of the
                                                                                           ICON_4CH


                                                                                      The external capacitors
                                                                                    (tipical value ~ 1nF) used
                                                                                   for AC-coupling are shown
                                                                                           in the middle




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                LOW POWER: power budget ~ 10W for ~ 103 channels
              Each front-end chipset has about 38 mW power consumption
                          and this means about 450mW for the hybrid.



              HIGH DYNAMIC RANGE: 105, range from 102 fC to 103 pC
                                    CURRENT CONVEYOR (split + mirror)
                                    TRIPLE RANGE




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                    MINIMAL CROSS-TALK:
            0.1% for input charge values below 100pC, 0.1-0.3% above


                                       ASIC-PMT DISTANCE:
                the board is connected to the PMT anodes through standard
                                          50 ohm coaxial cables
      • ==> The electronics can be located far away from the PMT
      • ==> minimum number of cables: signals + PMT power supply
      • ==> a lot of possibilities of implementation, e.g.: crate modules or
      stand-alone board.



                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                         FAULT TOLERANCE:
                                HYBRID BOARD:
                                    chip control lines are separated,
                                    no daisy-chains
                                 VME READ-OUT BOARD:
                                    one ADC for each VA chip,
                                    ADC control lines are separated




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                             POSSIBLE ADDITIONAL FEATURES:

             to give trigger capability to the system, a modified TA chip (from
                         TA32CG architecture) has been specified to:

         provide an analog output signal proportional to the number of input
        channels above a programmable threshold;

         provide an analog output signal proportional to the sum of 4 analog
        inputs (they can be chosen among the available 12 channels from the
        Icon chip when the die is mounted on the hybrid: this allows additional
        flexibility in the choice of the dynamic sub-range to be used for
        triggering purposes).




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002



                           Example of application: Trigger in Calorimeters




                         EM Event                                                  Hadron Event




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                                                                        Hybrid
                                                                                       on top of
                                                                                   VME read-out board



                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                                      PMT
                                         LED
                                                                                        Input
                                                                                       signal



     Pulse                                                                         Trigger      Hybrid
   generator




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                          1st range                                                               2nd range

                      6000                                                                      5000




                                                                                  output (mV)
  output (mV)




                      4000                                                                      3750
                                                                                                2500
                      2000                                                                      1250

                        0                                                                           0
                             0       50          100          150      200                              0              500      1000     1500

                                                                                                                   input charge (pC)
                                          input charge (pC)


                                          3rd range

                                                                                 Channel                    Expected Measured Measured
        output (mV)




                       3000
                                                                                                            gain ratio gain (mV/pC) gain ratio
                       2000
                                                                                                0             1:1             30         1
                       1000
                                                                                                1             1:8            3.5       0.12
                             0
                                                                                                2             1 : 80         0.35      0.012
                                 0   2000       4000      6000       8000

                                          input charge (pC)                   Tests performed with a R7600-00-M4 PMT

                                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                              branch                                     rms noise (fC)
                                1:1                                            49
                                1:8                                            408
                                1:80                                          4110


                           S/N ratio for a MIP of 0.8 pC: ~ 16

               Noise can be reduced in a future development by:

          decreasing the number of ranges from 3 to 2 for the ICON

          fixing the gain in the preamplifiers for the VA4

                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                         Cross-talk for R7600-00-M4 PMT is ~ 0.5%
                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




                                      Immediate applications:
     New generation space-based or balloon-borne experiments for
     the study of high energy primary cosmic rays (e.g.: AMS-02,
     CALET, CREAM, ... )




                                        M.G. Bagliesi University of Siena - INFN
A low-power high dynamic range front-end ASIC for imaging calorimeters
8th Workshop on Electronics for LHC Experiments - COLMAR, France -September 9 - 13, 2002




             LOW POWER CONSUMPTION: ~ 450mW
             HIGH DYNAMIC RANGE: ~105, from 102 fC to 103 pC
             MINIMAL CROSS-TALK: less then 0.3%
             BOARD-PMT DISTANCE
             FAULT TOLERANCE




                                        M.G. Bagliesi University of Siena - INFN

								
To top